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71.
星形胶质细胞As为中枢神经系统内多种胶质细胞中的一种.在正常中枢神经组织中,胶质细胞与神经元的比例是10:1~50:1,而星形胶质细胞在脑内数目最多,是中枢神经系统中最主要的大胶质细胞,并具有复杂多样的结构与功能.神经元-星形胶质细胞作为神经系统功能单位,它们之间的相互作用在中枢神经系统中非常重要,参与了中枢神经系统从胚胎发生到老化的各个活动,贯穿了神经元的整个发育过程.随着对中枢神经系统疾病病理机制和治疗手段的深入研究,人们认识到在神经系统发育、突触传递、神经组织修复与再生、神经免疫及多种神经疾病的病理方面都与星形胶质细胞密不可分.对星形胶质细胞的生物学功能及其与疾病的关系进行了较为系统的阐述,以期为相关疾病的临床治疗提供参考. 相似文献
72.
《Journal of Natural History》2012,46(18):2361-2375
A new species of solifuge from São Paulo State, south-eastern Brazil, is described, together with its phenology, habitat use, activity pattern and the effect of fire on the population. Mummucia coaraciandu n. sp. differs from other Mummuciidae in cheliceral dentition and pleurite coloration. Over a one-year period, 649 individuals of M. coaraciandu were captured in 72 pitfall traps distributed in three Cerrado physiognomies: borders of gallery forest (N=53), campo sujo (N=561) and campo cerrado (N=35). The species is diurnal and showed two peaks of surface activity during the year: the highest peak occurred in the cold–dry season (June to July) and the smaller peak in the middle of the warm–wet season (December to February). The number of individuals per trap was negatively correlated with the mean monthly temperature, but showed no correlation with the monthly precipitation. The sex ratio was male-biased (7:1) and the number of males trapped was positively correlated with the number of reproductive females. More individuals were trapped in burned areas when compared with unburned areas 1 month after the fire. This difference between the two areas was not observed 1 month before and 3–4 months after the passage of the fire (when the vegetation had recovered). Mummucia coaraciandu is the second solifuge described from the Brazilian Cerrado and its ecology is very similar to that of Mummucia mauryi from Caatinga vegetation. 相似文献
73.
《Journal of Natural History》2012,46(18):2211-2227
This study provides a detailed account of the natural history and foraging biology of the ponerine ant Dinoponera gigantea in a rainforest in north Brazil. The species nests on the ground and the colonies contain 70–96 workers. Ant activity is negatively correlated with temperature, and is more intense at dawn and dusk. Foragers leave the nest independently and search for food individually on the leaf litter, within ca 10 m around the nest. Workers are opportunistic feeders that collect seeds and fruits, and hunt for live prey as well as scavenge for dead animal matter. The dry weight of food items ranges from <10 mg (spiders, insect parts) to >400 mg (seeds, fruits). There is no nestmate recruitment during the search for or retrieval of food, irrespective of food type and size. Foragers have a high directional fidelity, and ants from neighbouring colonies may engage in ritualized territorial contests at the border of their foraging areas. The foraging ecology of D. gigantea is compared with other ponerine species living in tropical forests, as well as with other ant groups showing similar behavioural patterns. 相似文献
74.
This paper investigates Hermann Weyl’s reception of philosophical concepts stemming from the German Idealist Johann Gottlieb Fichte. In particular, Weyl’s ‘agens theory’ of matter, which he held around 1925, will be looked at. In the extant literature, the—admittedly also important—influence of Husserl on Weyl has mainly been addressed. Thus, apart from investigating some detailed Fichtean inheritances in Weyl’s concepts of causality, chance and continuity, the general difference which Weyl saw between the philosophies of Fichte and Husserl will also be discussed. For Weyl this is above all a difference between an active constructivism and a rather passive phenomenological seeing (Schau). Further, the paper shows in some detail the way Weyl was drawn into a certain reading of Fichte by his Zurich colleague, the philosopher Fritz Medicus. The methodological frame of the paper is that of Konstellationsforschung, a historical and systematic approach which proves to be particularly fruitful when investigating a (broadly speaking) German Idealist context and which allows special attention to be given to the acting subjects within the constellation under investigation. Conversely, Weyl’s agens theory suggests amendments to this methodology. 相似文献
75.
潘霏 《萍乡高等专科学校学报》2006,(2):88-90
电视媒体竞争除了在不断升级的内容竞争外,又掀起了一轮又一轮活动竞争的“热潮”。但在媒体活动“热潮”的背后凸现出了一些问题和误区。作为媒体活动成功的范例,央视《感动中国》评选活动的成功对于媒体活动的运作无疑是一个很好的借鉴和启示。 相似文献
76.
用普通煅烧方法和快速升温煅烧方法制备了C2S试样,并用扫描电子显微镜(SEM0直接观察了它们的水化情况,结果显示用快速升温方法制备的C2S具有较高的水化活性,该结论为改善C2S的水化活性提供了实事依据。 相似文献
77.
介绍了能够客观反映DCME(数字电路倍增设备)运行情况的8项主要统计参数,详细分析了每项参数的含义,给出了综合评价DCME倍增能力的计算方法及结果。 相似文献
78.
建立了强滴定弱碱混合液的通用滴定公式,并提出了进行活度校正的方法。利用该翁式可对滴定曲线作准确的模拟,以单纯形法优化计算混合碱各组份的浓度,使滴定曲线的计算PH值与实验值靠近,二者最接近时计算用混合碱组份浓度为它们在溶液当中的实际浓度。 相似文献
79.
漂盘培育云烟87和三生烟,苗期接种TMV后0h,12h,24h,36h,48h,60h和72h分别取样测定其叶片和根系中PAL的活性,并以未接种TMV烟苗叶片和根系中PAL的活性为对照.结果表明:烟草与TMV非亲和性互作时,叶片和根系中PAL活性上升速度比烟草与TMV亲和性互作时PAL活性上升速度快;烟草与TMV无论是亲和性互作还是非亲和性互作,烟草叶片中PAL活性升高速度快于根系中PAL活性上升速度. 相似文献
80.
文章强调县级图书馆开展读者活动的重要性,分析了影响县级图书馆开展读者活动的因素,提出了县级图书馆策划和组织读者活动的方法以及应注意的问题。 相似文献